Air pipe line distribution system

ABSTRACT

The invention relates to a refinement of an air guiding system for an internal combustion engine, having an intake conduit which adjoins an air inlet opening downstream and is part of a gas guiding chamber that carries air from the air inlet opening to an outlet opening. In the air guiding system, an air filter is embodied as an interchangeable cartridge in such a way that the air filter is insertable into and removed from the intake conduit.

The invention is based on an air guiding system for an internalcombustion engine.

The air guiding system is intended for an internal combustion engine ofa motor vehicle. One such air guiding system is known from German Patent38 42 248, for example. The known air guiding system has an air inletopening, an intake conduit adjoining the air inlet opening downstream,and an outlet opening connected to a gas inlet opening of the combustionchamber of an internal combustion engine. The outlet opening is locateddownstream of an outlet conduit. The intake conduit and the outletconduit are embodied as a diffusor, in order to provide noise abatement.Downstream of the intake conduit or upstream of the outlet conduit,there is a deflection chamber that deflects the gas stream by 180° fromthe intake conduit into the outlet conduit. Also located at the inlet tothe outlet conduit is an air filter for filtering the air, flowingthrough the air guiding system, for the engine; the air filter isaccessible only by removing the housing of the deflection chamber.

A disadvantage of the known air guiding system is that the air filter isrelatively poorly accessible, and installing and removing the air filterentails relatively major assembly effort and expense. Moreover, the airfilter has a relatively small usable filter area, so that the air streamin the air guiding system is exposed to a relatively high flowresistance in the region of the filter. Another disadvantage of theknown air guiding system is that it requires a relatively large amountof space in the engine compartment of the motor vehicle, and arelatively large installation space must therefore be made available forthe air guiding system.

ADVANTAGES OF THE INVENTION

The air guiding system according to the invention has the advantage overthe prior art that the air filter can be installed in the air guidingsystem without a major assembly effort and expense and if maintenance isneeded can be replaced relatively simply. The intake conduit actssimultaneously as a housing for the air filter, so that the hollow spacein the intake conduit is utilized as a filter chamber. A high packingdensity of the components in the intake region of the air guiding systemis thereby attained, and the installation space required for the airguiding system is reduced further. Overall, an extremely compact designof the air guiding system is attained, and at the same time thevolumetric region through which unfiltered crude air flows is reduced toa minimum.

The intake conduit may be closable with a cap on the side toward the airinlet opening, so that once the cap is removed the air filter can bereplaced with only a few manual operations.

The air filter is preferably embodied as a component which is orientedaxially to the longitudinal axis of the intake conduit and which devidesan axial inner chamber from a peripheral outer chamber. Because of theaxial alignment of the air filter, an especially large filter area isachieved, and as a result the flow resistance exerted by the air filteris advantageously reduced. An especially compact and at the same timedimensionally stable component is obtained if the air filter is embodiedin the form of a hollow cylinder.

For an air guiding system with a gas guiding chamber which has onewormlike curved region and one region ducted through the wormlike curvedregion, an especially space-saving overall arrangement is obtained ifthe intake conduit that receives the air filter is integrated with theducted region. In this way, the volume already present inside thewormlike curved region is utilized in an optimally space-saving way. Athrottle device may also be integrated into the air guiding systemwithout a major effort or expense.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferably selected and especially advantageous exemplary embodiments ofthe invention are shown in the drawing in simplified form and describedin further detail in the ensuing description. Shown are:

FIG. 1, a longitudinal section through an exemplary embodiment of theair guiding system;

FIG. 2, a cross section through an exemplary embodiment of the airguiding system that has essentially the same structure as FIG. 1;

FIG. 3, a perspective view of an air guiding system corresponding to theexemplary embodiment shown in FIG. 2;

FIG. 4, a longitudinal section through the intake conduit of a furtherexemplary embodiment of an air guiding system; and

FIG. 5, a longitudinal section through an air guiding systemcorresponding to a further exemplary embodiment.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

The air guiding system embodied according to the invention may beprovided in various internal combustion engines. The engine is forinstance a motor to which air or a fuel-air mixture is delivered via theair guiding system. The air guiding system can be structurally combinedwith various components required for operating the engine.

The engine is for instance an aspirating engine, in which air isaspirated as a result of a suitable motion of the pistons. However, itis also possible in addition to provide a unit that delivers the air tothe engine under pressure.

The engine preferably has a plurality of cylinders, but in principle itmay also be an internal combustion engine with a single cylinder.

Although the engine may be of various types and can be used to drivevarious machines, for the sake of simplicity in the ensuing descriptionof the exemplary embodiments it will be assumed that the engine operateson the principle of an Otto engine, is an aspirating engine, isinstalled in the engine compartment of a motor vehicle, and serves todrive the motor vehicle. It will also be assumed that the engine hasfour inline cylinders, with the line of the four cylinders beinginstalled crosswise to the travel direction of the motor vehicle.

FIG. 1 shows a longitudinal section through an air guiding system of theinvention. The sectional plane shown extends crosswise to the traveldirection of the motor vehicle.

FIG. 2 shows a cross section longitudinally of the motor vehicle traveldirection through an air guiding system, which is substantiallystructurally identical to the air guiding system shown in FIG. 1.

For the sake of greater simplicity, the sectional faces shown in FIGS. 1and 2 are not each in a single plane but rather extend with multiplegraduations, to make the most essential features of the invention asclearly apparent as possible.

FIG. 3 is a view on the air guiding system of FIG. 2, looking obliquelytoward the front from somewhat above the air guiding system.

In all the drawing figures, identical or identically functioning partsare identified by the same reference numerals. Unless anything to thecontrary is mentioned or shown in the drawing, what is said and shownfor one of the drawings applies to all the exemplary embodiments. Unlessotherwise noted in the explanations, the details of the variousexemplary embodiments can be combined with one another. The air guidingsystem 2 embodied in exemplary fashion and preferably selected for thedescription and drawing is composed essentially of a first air guidingpart 4, a second air guiding part 6, a tube 8, and a design hood 10. Inapproximate terms, the first air guiding part 4, the second air guidingpart 6, the tube 8 and the design hood 10 are the main components of theair guiding system 2.

In the ensuing description, the drawing figure is given in parenthesesthat shows that particular detail especially clearly.

The internal combustion engine selected has four cylinders and has acylinder head 12. Of the engine, a small portion of a section throughthe cylinder head 12 is shown (FIG. 2). For the sake of simplicity,essentially only the outlines of the section through the cylinder head12 are shown.

The cylinder head 12 belongs to an engine having at least one cylinder.Located in the cylinder are a displaceably supported piston (not shown,for the sake of simplicity), and a combustion chamber (also not shown,for the sake of simplicity). A gas inlet opening 14 leads into thecombustion chamber of the engine. Through the gas inlet opening 14, airor a fuel-air mixture can reach the combustion chamber.

The air guiding system 2 has an air inlet opening 16 (FIGS. 1, 2) and anoutlet opening 18 (FIG. 2). A gas guiding tube leads through the airguiding system 2. The gas guiding tube will hereinafter be called thegas guiding chamber 20. The gas guiding chamber 20 begins at the airinlet opening 16 and leads via the outlet opening 18 into the gas inletopening 14 of the cylinder head 12 of the engine.

Through the gas guiding chamber 20, air can flow in through the airinlet opening 16 and reach the combustion chamber of the engine. In thecourse of the air guiding system 2, air flowing through it can have fuelor a mixture added to it, depending on the type of engine and as needed.

To simplify the explanations of the exemplary embodiments, the gasguiding chamber 20 will be thought of as being divided into a pluralityof parts. In accordance with this imaginary division, the gas guidingchamber 20 includes first an air inlet opening 16, which is adjoineddownstream by an intake conduit 22 (FIGS. 1, 2). The intake conduit 22serves at the same time as the filter installation space and receives anair filter 200, which will be described in further detail hereinafter.The intake conduit 22 is followed in the flow direction by threeconnecting conduits 23 (FIG. 1). In a post-filter chamber 26, theconnecting conduits 23 come together again. Downstream of thepost-filter chamber 26 is a calming conduit 27 (FIGS. 1, 2). The calmingconduit 27 is followed by a connecting conduit 28 (FIG. 1). Theconnecting conduit 28 is located substantially inside the flexible tube8. The connecting conduit 28 ends downstream in a throttle device 29(FIGS. 1, 3). This is followed downstream by a connecting stub 30 (FIGS.1, 3). The connecting stub 30 discharges into a gas distribution chamber31 (FIGS. 1, 2). From the gas distribution chamber 31, a conduit 32branches off (FIGS. 1, 2, 3). The conduit 32 carries the medium flowingthrough the air guiding system 2, or some of this medium, out of the gasdistribution chamber 31 through the outlet opening 18 and through thegas inlet opening 14 into the combustion chamber of the engine. Becausethe preferably selected air guiding system 2 is provided as an examplefor an internal combustion engine with four combustion chambers, threefurther conduits 32 a, 32 b, 32 c (FIGS. 1, 3) branch off from the gasdistribution chamber 31, parallel to the conduit 32; each of theconduits 32, 32 a, 32 b, 32 c leads to a respective combustion chamberof the four-cylinder engine.

The intake conduit 22 and in part the connecting conduits 23 belong to aregion of the air guiding system 2 that will hereinafter be called theducted region 38.

The conduits 32, 32 a, 32 b, 32 c, in terms of the longitudinaldirection of the gas distribution chamber 31, branch off from the gasdistribution chamber 31 virtually vertically. The conduits 32, 32 a, 32b, 32 c form a wormlike curved region 40 (FIG. 2) of the air guidingsystem 2. In approximate terms, the curved region 40 can be imagined asbeing divided into a first portion 41, a second portion 42, and a thirdportion 43.

The first portion 41, in terms of the flow direction, begins at thebranching point of the conduits 32, 32 a, 32 b, 32 c from the gasdistribution chamber 31. In the first portion 41, the conduits 32, 32 a,32 b, 32 c communicate with one another via a wall 46 (FIG. 1). Thefirst portion 41 of the conduits 32, 32 a, 32 b, 32 c (FIG. 1) islocated on the outward-facing side of the wall 46, and the intakeconduit 22 is located on the inward-facing side of the wall 46. The wall46 partitions the intake conduit 22 off from the environment, and thewall 46 also serves to partition off the conduits 32, 32 a, 32 b, 32 cfrom the intake conduit 22. In the first portion 41, the conduits 32, 32a, 32 b, 32 c extend in an arc (a wide-angled arc of approximately 90°in the viewing direction of FIG. 2). The arc is followed by a shortstraight piece. The end of the first portion 41 is placed in imaginaryterms against the end of the straight piece.

The second portion 42 of the curved region 40 adjoins the first portion41. In the second portion 42, the conduits 32, 32 a, 32 b, 32 c areextended in a further arc (right-angled curve of approximately 120°, forinstance, in the viewing direction of FIG. 2). In the second portion 42,the conduits 32, 32 a, 32 b, 32 c are spaced apart from one another suchthat gaps ensue between the conduits 32, 32 a, 32 b, 32 c, which gapsserve the connecting conduits 23 for connecting the intake conduit 22 tothe post-filter chamber 26 (FIG. 1). The air from the intake conduit 22can flow in the direction of the post-filter chamber 26 through the gapsbetween the spaced-apart conduits 32, 32 a, 32 b, 32 c.

The second portion 42 is adjoined by the third portion 43 (FIG. 2). Inthe third portion 43, the conduits 32, 32 a, 32 b, 32 c are thensubstantially straight, until each of the conduits 32, 32 a, 32 b, 32 cends at a respective outlet opening 18. The conduits 32, 32 a, 32 b, 32c are curved in wormlike fashion. In the three portions 41, 42, 43, theconduits 32, 32 a, 32 b, 32 c are curved by a total of 180°, forinstance. As FIG. 1 shows, the conduits 32, 32 a, 32 b, 32 c may inparticular also be curved by more than 180°. The so-called wormlikecurved region 40 at least partially encloses the ducted region 38.

At the cylinder head 12 of the engine, there is a chamber 48 (FIG. 2).Located in the chamber 48 are for instance the usual inlet valves,outlet valves, and the control shaft for controlling the inlet andoutlet valves, that are usual in an internal combustion engine. Thecontrol shaft and inlet and outlet valves are not shown, for the sake ofgreater simplicity. The chamber 48 (FIG. 2) is covered with the aid of acylinder head hood 50 (FIG. 2).

The cylinder head hood 50 is shaped such that it serves both to coverthe chamber 48 of the cylinder head 12 and to form the second airguiding part 6 of the air guiding system 2. In other words, the secondair guiding part 6 is shaped such that it both is a component of the airguiding system 2 and acts to cover the chamber 48 of the engine. Thesecond air guiding part 6 with the cylinder head hood 50 formed onto itcan be made in an integrally cohesive way from an injection mold. Thematerial of the second air guiding part 6 is preferably plastic.

The post-filter chamber 26 is sealed off from the design hood 10 by anencompassing seal 58 (FIGS. 1, 2).

A connection opening 64 (FIG. 1) is formed onto the second air guidingpart 6. The connection opening 64 discharges into the calming conduit27. A flow rate meter may be provided in the connection opening 64. Theflow rate meter can sense the volume flowing per unit of time throughthe gas guiding chamber 20 or the mass of air flowing per unit of timethrough the gas guiding chamber 20 and furnish an electrical signalaccordingly to an electronic system, not shown. Along with or instead ofthe flow rate meter, a thermometer that measures the temperature of theair flowing through may also be installed in the connection opening 64.

Upstream of the flow rate meter 66, a screen 68 (FIG. 1) made of metaland/or a flow lattice 68 molded from plastic are provided in the calmingconduit 27. The screen 68 and the flow lattice 68 a promote the calmingof the air flowing to the flow rate meter.

The second air guiding part 6 of the air guiding system 2, which alsotakes on the function of the cylinder head hood 50, is connected to thecylinder head 12 of the engine via a fastening means 70 (FIG. 2), or aplurality of fastening means 70. The fastening means 70 is in the formof a screw or a plurality of screws, for instance, with which the airguiding part 6 is solidly connected to the engine. Between the cylinderhead 12 and the air guiding part 6, an encompassing cylinder head seal72 (FIG. 2) is provided, which seals off the chamber 48 from theenvironment.

The second air guiding part 6 is connected solidly, but separably asneeded, to the first air guiding part 4 via a fastening means 74 (FIG.2). The fastening means 74 for instance includes a clamp or a pluralityof clamps distributed over the circumference. The clamps of thefastening means 74 are pivotably supported on the second air guide part6, for instance, and once the second air guide part 6 is mounted on thefirst air guiding part 4, these clamps can be snapped into place oncorresponding cams provided on the first air guiding part 4. Between thefirst air guiding part 4 and the second air guiding part 6, a housingseal 76 is provided (FIGS. 1, 2). The housing seal 76 seals off the gasguiding chamber 20 from the environment.

The design hood 10 is mounted on the second air guiding part 6. Theshapes of the design hood 10 and the second air guiding part 6 areadapted to one another such that a hollow chamber, which a component ofthe post-filter chamber 26, forms between the design hood 10 and thesecond air guiding part 6. The hollow chamber between the design hood 10and the second air guiding part 6 extends not only in the regionimmediately downstream of the conduits 32, 32 a, 32 b, 32 c, but thishollow chamber also extends far into the region located above thecylinder hood 50 that covers the chamber 48. As a result, an additionalchamber 78 (FIG. 2) is created between the design hood 10 and the secondair guiding part 6. The chamber 76 is located not directly in the airflow but rather somewhat aside from it. Intermediate ribs are providedbetween the design hood 10 and the air guiding part 6 for reinforcementpurposes. There are openings in the intermediate ribs, so that theadditional chamber 78 communicates directly with the gas guiding chamber20. The additional chamber 78 increases the usable volume of the gasguiding chamber 20. This has considerable effects on the noise producedby the engine. Because the gas guiding chamber 20 can be designed asrather large even when external space conditions are restricted, thenoise produced by the air guiding system 2 or the engine can be reducedsubstantially.

The design hood 10 is solidly, but if needed separably, connected to thesecond air guiding part 6 via a fastening means 80 (FIG. 2). Thefastening means 80 for instance includes a hinge 80 a or a plurality ofhinges 80 a, a screw 80 b or a plurality of screws 80 b, and a clamp 80c or a plurality of clamps 80 c. Depending on the number of screws 80 b,the fastening means also includes a nut thread 80 d (FIG. 2) or aplurality of nut threads 80 d, formed onto the air guiding part 6 or cutonto it, for screwing in the screw 80 b or screws 80 b for fastening thedesign hood 10 to the air guiding part 6. After the clamp 80 c and thescrew 80 b have been loosened, the design hood 10 can be pivotedrelative to the air guiding part 6.

At points of contact between the design hood 10 and the second airguiding part 6, an encompassing seal 82 is provided. The seal 82 is alsomounted on the intermediate ribs between the air guiding part 6 and thedesign hood 10.

The cylinder head seal 72, the housing seal 76 between the two airguiding parts 4 and 6, and the seal 82 all serve to provide sealing andacoustical decoupling among the various structural parts and thus have anoise-abating effect.

In the air guiding system 2, a fuel delivery opening 84 (FIG. 2) isprovided. As the preferably selected exemplary embodiment shows, thefuel delivery opening 84 leads into the gas guiding chamber 20 in theregion of the outlet opening 18. Depending on the number of conduits 32,32 a, 32 b, 32 c, a corresponding number of fuel delivery openings 84 isprovided.

A fuel distributor strip 86 (FIG. 2) is mounted on the air guidingsystem 2. The fuel distributor strip 86 includes a fuel tube 88, anelectromagnetically actuatable injection valve 90 (FIG. 2), and a fuelstub 92. One injection valve 90 is inserted into each of the fueldelivery openings. Each of these four injection valves 90 branches offfrom the fuel tube 88. For the sake of simplicity, only one of theinjection valves 90 is shown in FIG. 2. Via a fuel pump, not shown, thefuel flows via the fuel stub 92 into the fuel tube 88. Between the firstair guiding part 4 and the second air guiding part 6, a hollow chamber94 is formed, extending along the cylinders, for instance four innumber, of the engine. The fuel distributor strip 86 having theinjection valves 90 can be disposed in this hollow chamber 94.

In FIG. 2, a dot-dashed line 98 that is bent several times at an angleis shown. The dot-dashed line 98 on the one hand and the cylinder head12 of the engine on the other define an installation space 100. Anotherreason is because the air guiding system 2 has both the wormlike curvedregion 40 and the ducted region 38 that is ducted at least partlythrough the inside of the wormlike curved region 40 and thatsubstantially includes the intake conduit 22, the particularly goodutilization of the available installation space 100 is achieved.

The tube 8 is connected by its upstream end to the calming conduit 27(FIG. 1) formed onto the air guiding part 6, and downstream the tube 8is connected to the throttle device 29. The throttle device 29 ismechanically coupled to the first air guiding part 4. Via the elastichousing seal 76, the two air guiding parts 4 and 6 are largely decoupledin terms of vibration and acoustically. The tube 8 is elastic andtherefore does not hinder the vibrational decoupling between the two airguiding parts 4 and 6, or hinders it only insignificantly. The throttledevice 29 for includes a throttle valve 29 b (FIG. 1) pivotablysupported in a throttle valve stub 29 a. The position of the throttlevalve 29 b is variable, for instance with the aid of an electricallycontrollable actuator 29 c (FIG. 3). The throttle device 29, whichincludes the throttle valve stub 29 a, the throttle valve 29 b, and theactuator 29 c, can be flanged as a complete unit to the first airguiding part 4 of the air guiding system 2.

A retaining device 102 (FIG. 3) is provided on the preferred example ofan air guiding system 2 shown. Via the retaining device 102, a tankventing valve can for instance be secured to the air guiding system 2.The retaining device 102 is formed onto the connecting stub 30 of thefirst air guiding part 4, for instance. When assembled, the air guidingsystem 2 forms a functional unit for an internal combustion engine andcan therefore also be called an air guiding module.

A flange face 102 (FIG. 2) is provided on the first air guiding part 4.There is a counterpart flange face on the engine. The first air guidingpart 4 can be secured to the counterpart flange face of the engine bythe flange face 104. Fastening means, especially screws, not shown inthe drawing are used for this purpose.

In the exemplary embodiment shown, the four injection valves 90 areprovided in order to meter fuel separately to each cylinder of theengine. It should be pointed out that the air guiding system 2 may alsobe embodied such that fuel is delivered at some other point of the airguiding system 2. For instance, it is possible to inject fuel into thegas-guiding chamber 20 in the region of the throttle device 29, in whichcase the fuel mixes intensively with the air in the region of thethrottle device 29 and is delivered together with the air to thecombustion chambers of the engine. The possibility also exists ofinjecting the fuel, via injection valves, not shown, not into the airguiding system 2 but rather directly into the combustion chambers of theengine.

In the first air guiding part 4, there is a curved first dividing plane106 and a curved second dividing plane 108 (FIG. 2). For the sake ofeasy production of the air guiding part 4 using casting techniques, theair guiding part 4 is made from three cast or injection-moldedindividual parts, which are welded together or adhesively bonded to oneanother after the casting or injection molding. Because both the firstair guiding part 4 and the second air guiding part 6 are preferably ofplastic, it is easily possible to weld or adhesively bond the threeindividual parts to one another.

According to the invention, the air filter 200 is embodied as aninterchangeable cartridge and is insertable directly into the intakeconduit 22 of the air guiding system 2 that adjoins the air inletopening 16. The cartridge-like embodiment of the air filter 200 allowseasy, fast replacement. The disposition of the air filter 200 in theintake conduit 22 immediately downstream of the air inlet opening 16 hasthe advantage that the air is already filtered in the inlet region ofthe air guiding system 2, and the crude air chamber of the air guidingsystem 2 that contains unfiltered air is reduced to a region of minimalvolume. This accordingly prevents soiling of the air guiding system 2even under extreme conditions of use. In the exemplary embodiment shownin FIGS. 1 and 2, the air filter 200 is embodied hollow-cylindrically.The air filter 200 radially surrounds an inner chamber 201, whichextends in the axial direction of the intake conduit 22 in the interiorof the air filter 200; the air filter 200 divides a peripheral outerchamber 202 from the inner chamber 201 (FIGS. 1, 2).

For replacement of the air filter 200, the intake conduit 22 has a cap203 (FIG. 1), which in the exemplary embodiment includes an intake stub204 in which the air inlet opening 16 is embodied. The cap 203 is joinedto a flange 205 of the intake conduit 22, for instance by screwing (FIG.1), and is sealed off from the flange 205, for instance by the placementof an O-ring or some other suitable sealing means. The cap 203 at thesame time serves as a retainer for the air filter 200 inserted into theintake conduit 22. To that end, the cap 203 has suitable retainingdevices, for instance in the form of a preferably radially encompassingprotrusion 206. In the exemplary embodiment shown, the air filter 200,on its end 207 toward the cap 206, is locked on the outside on thisprotrusion 206, because the protrusion 206 encloses the air filter 200on the outside. The wall 208 of the intake conduit 22 opposite the cap203 has a corresponding retaining device, for locking the air filter 200on its end 209 opposite the cap 203. In the exemplary embodiment, thisretaining device is embodied as a radially encompassing protrusion 210,which on the inside encloses the air filter 200 on its end 209 oppositethe cap 203 (FIG. 1).

For replacement of the air filter 200 embodied as an interchangeablecartridge, the cap 203 need merely be removed, and after that the airfilter is freely accessible and can be grasped. Upon insertion of theair filter 200, the air filter is introduced into the intake conduit 22and slipped onto the protrusion 210. The cap 203 is then placed on theflange 205, so that the air filter 200 is at the same time inserted intothe radial inner region of the protrusion 206. Alternatively, theprocedure may also be such that the air filter 200 is first insertedinto the radial inner region of the protrusion 206 of the cap 203 andthat the air filter 200 is clamped together with the cap 203 in thisway. The air filter 200 is then introduced into the intake conduit 22far enough that the cap 203 rests on the flange 205, and at the sametime the end 209 of the air filter 200 opposite the cap 203 is engagedby the protrusion 210. The guidance of the air filter 200 in the intakeconduit 22 can be facilitated by providing that the protrusions 210 haveconical regions 211, which center the air filter 200 (FIG. 1).

The crude air region of the air guiding system 2 embodied according tothe invention includes only the air inlet opening 16 and the innerchamber 201 of the air filter 200. Any dirt particles that may beaspirated are retained by the air filter 200 and either remain stuck tothe filter material, or if the aspirated air is heavily soiled, theycollect in the inner chamber 201. When the air filter 200 embodied as aninterchangeable cartridge is replaced, the dirt particles that mighthave collected in the inner chamber 201 are therefore also removed fromthe intake conduit 22 along with the air filter 200, so thatcontamination of the air guiding system 2 when the air filter 200 isbeing replaced is effectively avoided. Moreover, the volume of the crudeair region is reduced to a minimum, so that the air guiding system 2does not become soiled at any point and can therefore be operatedwithout maintenance even under extreme conditions of use. Because of theintegration of the air filter 200 with the intake conduit 22, or thefunctional expansion of the intake conduit 22 as a filter housing forthe air filter 200, the degree of integration of the air guiding system2 is increased further, and an especially compact design with optimalutilization of the available installation space 100 is achieved. Theexemplary embodiment shown in FIG. 1 is also distinguished in that theintake conduit 22 together with the air filter 200 is disposed in theregion 38 that is ducted through the conduits 32, 32 a, 32 b, 32 c ofthe wormlike curved region 40. This makes an especially space-saving,compact design of the air guiding system 2 possible.

For the sake of better comprehension of the invention, the air flow inthe air guiding system 2 is represented by arrows in FIGS. 1 and 2. Thismakes it clear that the crude air first flows via the air inlet opening16 to the inner chamber 201 and then flows, with a radiallyoutward-oriented flow component, through the air filter 200 into theperipheral outer chamber 202.

FIG. 4 shows a further exemplary embodiment of the invention in the formof a basic sketch. In contrast to the exemplary embodiment describedabove, in the exemplary embodiment shown in FIG. 4 the air flow iscarried such that the air flows from the peripheral outer chamber 202with a radially inward-oriented flow component through the air filter200 into the axial inner chamber 201. The radial flow direction throughthe air filter 200 is accordingly the reverse of the exemplaryembodiment described earlier above.

In order to achieve this flow course, the air inlet opening 16 isdisposed on the outside in the cap 203, so that the aspirated air firstflows into the peripheral outer chamber 202. After flowing through theair filter 200, the cleaned air is carried away from the axial innerchamber 201 via an intake conduit outlet opening 220 located on the end209 of the air filter 200 opposite the cap 203. To that end, the well208 of the intake conduit 22 has a tubular outlet stub 221, in which theintake conduit of 220 is embodied. The airflow is clearly shown bycorresponding arrows in FIG. 4. The cap 203 can be joined to the flange205 by fast-release clamping elements, for instance by means of merelyschematically shown closure clamps 222. The outlet stub 221 at the sametime acts as a retaining device for the end 209 of the air filter 200opposite the cap 203. As a retaining device for the end 207 of the airfilter 200 toward the cap 203, the cap 203 has a protrusion 223. In thisway, the air filter 200 is locked centrally in the intake conduit 22.

FIG. 5 shows a realization of the exemplary embodiment shown onlyschematically in FIG. 4, here in the case of an air guiding system 2that has substantially the same basic design as the exemplary embodimentshown in FIG. 1. A cup-shaped filter retainer 230 is formed onto theinside of the cap 230. The filter retainer 230 locks the air filter 200on its end 207 toward the cap 203. The filter retainer 230 also has atermination plate 231, which seals off the interior 201 of the airfilter 200 from a prefilter chamber 232 following the air inlet opening16. The cup-shaped filter retainer 230 also has through openings 233, inorder to make the prefilter chamber 232, communicating with the airinlet opening 16, communicate with the peripheral outer chamber 202 ofthe air filter 200. The aspirated crude air then flows first via the airinlet opening 16 into the prefilter chamber 232 and then through thethrough openings 233 into the peripheral outer chamber 202 of the airfilter 200. The air then flows through the air filter 200 with aradially inward-oriented flow component, as has already been explainedin conjunction with FIG. 4. The filtered air flows via an elbow 234,which communicates via a communication opening 235 with the axial innerchamber 201, into the post-filter chamber 26. The further course of theair flow is equivalent to the flow course already explained inconjunction with FIG. 1. The elbow 234 is sealed off from the second airguiding part 6 via the housing seal 76 and an additional seal 236.

Manifold embodiments of the air filter 200 and the associated retainingdevices within the intake conduit 22 are conceivable within the scope ofthe invention. The air filter 200 need not necessarily behollow-cylindrical at all. For instance, it is readily conceivable toembody the air filter 200 with a rectangular cross section, and inparticular a square cross section. The air filter 200 can also becompletely closed on one of its two face ends, in the form of apouchlike embodiment. It is also conceivable for a pouchlike air filter200 to be disposed in the intake conduit 22 in such a way that the crudeair flowing in via the air inlet opening 16 inflates the intake conduit22 like a vacuum cleaner. It can then suffice merely to secure the airfilter 200 sealingly in the cap 203, so that the pouchlike air filter200 is removed from the intake conduit when the cap 203 is removed.

The foregoing relates to a preferred exemplary embodiment of theinvention, it being understood that other variants and embodimentsthereof are possible within the spirit and scope of the invention, thelatter being defined by the appended claims.

What is claimed is:
 1. An air guiding system for an internal combustionengine, which has at least one combustion chamber with at least one gasinlet opening leading into the combustion chamber, comprising an airinlet opening (16), an intake conduit (22) adjoining the air inletopening (16) downstream, an outlet opening (18) connected to the gasinlet opening of the combustion chamber, a gas guiding chamber (20) thatguides air from the air inlet opening (16) to the outlet opening (18),and an air filter (200) provided in the gas guide chamber (20), the airfilter (200) is embodied as an interchangeable cartridge that can beinserted into and removed from the intake conduit (22), the gas guidingchamber (20) has a curved region (40) shaped in wormlike form, in whichthe wormlike curved region (40) is part of a wall of the intake conduit(22), and the intake conduit (22) receiving the air filter (200) isdisposed in a ducted region (38), which is ducted through the wormlikecurved region (40).
 2. The air guiding system of claim 1, in which theintake conduit (22) is closable with a cap (203) containing the airinlet opening (16), in such a way that the air filter (200) is insertedinto and removed from the intake conduit (22) when the cap (203) hasbeen removed.
 3. The air guiding system of claim 1, in which the airfilter (200) surrounds an inner chamber (201) that is axial with regardto the longitudinal axis of the intake conduit (22) and divides theinner chamber (201) from a peripheral outer chamber (202).
 4. The airguiding system of claim 3, in which the air flows via the air inletopening (16) to the inner chamber (201) and flows with a radiallyoutward-oriented flow component through the air filter (200) into theperipheral outer chamber (202).
 5. The air guiding system of claim 3, inwhich the air flows via the air inlet opening (16) to the peripheralouter chamber (202) and flows with a radially outward-oriented flowcomponent through the air filter (200) into the inner chamber (201). 6.The air guiding system of claim 3, in which the air filter (200) isembodied substantially in the form of a hollow cylinder.
 7. The airguiding system of claim 4, in which the air filter (200) is embodiedsubstantially in the form of a hollow cylinder.
 8. The air guidingsystem of claim 5, in which the air filter (200) is embodiedsubstantially in the form of a hollow cylinder.
 9. The air guidingsystem of claim 1, in which retaining devices (210, 206; 210, 230) forreceiving and orienting the air filter (200) are provided on the wall ofthe intake conduit (22).
 10. The air guiding system of claim 2, in whichretaining devices (210, 206; 210, 230) for receiving and orienting theair filter (200) are provided on the wall of the intake conduit (22).11. The air guiding system of claim 3, in which retaining devices (210,206; 210, 230) for receiving and orienting the air filter (200) areprovided on the wall of the intake conduit (22).
 12. The air guidingsystem of claim 2, in which one group of the retaining devices (206;230) are provided on the cap (203), and another group of the retainingdevices (210) are provided on the wall (208) of the intake conduit (22)opposite the cap (203), in order to lock the air filter (200) on each ofits two respective ends (207, 209).
 13. The air guiding system of claim11, in which one group of the retaining devices (206; 230) are providedon the cap (203), and another group of the retaining devices (210) areprovided on the wall (208) of the intake conduit (22) opposite the cap(203), in order to lock the air filter (200) on each of its tworespective ends (207, 209).
 14. The air guiding system of claim 1, inwhich a throttle device (29) is provided downstream of the air filter(200).
 15. The air guiding system of claim 2, in which a throttle device(29) is provided downstream of the air filter (200).
 16. The air guidingsystem of claim 3, in which a throttle device (29) is provideddownstream of the air filter (200).
 17. The air guiding system of claim1, in which the wormlike curved region (40) is divided into a pluralityof conduits (32, 32 a, 32 b, 32 c), which each at least partiallyenclose the intake conduit (22).
 18. The air guiding system of claim 14,in which the throttle device (29) is disposed between the air filter(200) and the wormlike curved region (40).
 19. The air guiding system ofclaim 17, in which between the plurality of conduits (32, 32 a, 32 b, 32c) a wall is provided that closes off the intake conduit 22 from anoutside.